drivers/s390/cio/cio.c

   1 /*
   2  *  drivers/s390/cio/cio.c
   3  *   S/390 common I/O routines -- low level i/o calls
   4  *
   5  *    Copyright (C) IBM Corp. 1999,2006
   6  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
   7  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   8  *               Arnd Bergmann (arndb@de.ibm.com)
   9  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/slab.h>
  15 #include <linux/device.h>
  16 #include <linux/kernel_stat.h>
  17 #include <linux/interrupt.h>
  18 #include <asm/cio.h>
  19 #include <asm/delay.h>
  20 #include <asm/irq.h>
  21 #include <asm/irq_regs.h>
  22 #include <asm/setup.h>
  23 #include <asm/reset.h>
  24 #include <asm/ipl.h>
  25 #include <asm/chpid.h>
  26 #include <asm/airq.h>
  27 #include <asm/cpu.h>
  28 #include "cio.h"
  29 #include "css.h"
  30 #include "chsc.h"
  31 #include "ioasm.h"
  32 #include "io_sch.h"
  33 #include "blacklist.h"
  34 #include "cio_debug.h"
  35 #include "chp.h"
  36 #include "../s390mach.h"
  37
  38 debug_info_t *cio_debug_msg_id;
  39 debug_info_t *cio_debug_trace_id;
  40 debug_info_t *cio_debug_crw_id;
  41
  42 /*
  43  * Function: cio_debug_init
  44  * Initializes three debug logs for common I/O:
  45  * - cio_msg logs generic cio messages
  46  * - cio_trace logs the calling of different functions
  47  * - cio_crw logs machine check related cio messages
  48  */
  49 static int __init cio_debug_init(void)
  50 {
  51         cio_debug_msg_id = debug_register("cio_msg", 16, 1, 16 * sizeof(long));
  52         if (!cio_debug_msg_id)
  53                 goto out_unregister;
  54         debug_register_view(cio_debug_msg_id, &debug_sprintf_view);
  55         debug_set_level(cio_debug_msg_id, 2);
  56         cio_debug_trace_id = debug_register("cio_trace", 16, 1, 16);
  57         if (!cio_debug_trace_id)
  58                 goto out_unregister;
  59         debug_register_view(cio_debug_trace_id, &debug_hex_ascii_view);
  60         debug_set_level(cio_debug_trace_id, 2);
  61         cio_debug_crw_id = debug_register("cio_crw", 16, 1, 16 * sizeof(long));
  62         if (!cio_debug_crw_id)
  63                 goto out_unregister;
  64         debug_register_view(cio_debug_crw_id, &debug_sprintf_view);
  65         debug_set_level(cio_debug_crw_id, 4);
  66         return 0;
  67
  68 out_unregister:
  69         if (cio_debug_msg_id)
  70                 debug_unregister(cio_debug_msg_id);
  71         if (cio_debug_trace_id)
  72                 debug_unregister(cio_debug_trace_id);
  73         if (cio_debug_crw_id)
  74                 debug_unregister(cio_debug_crw_id);
  75         printk(KERN_WARNING"cio: could not initialize debugging\n");
  76         return -1;
  77 }
  78
  79 arch_initcall (cio_debug_init);
  80
  81 int
  82 cio_set_options (struct subchannel *sch, int flags)
  83 {
  84        sch->options.suspend = (flags & DOIO_ALLOW_SUSPEND) != 0;
  85        sch->options.prefetch = (flags & DOIO_DENY_PREFETCH) != 0;
  86        sch->options.inter = (flags & DOIO_SUPPRESS_INTER) != 0;
  87        return 0;
  88 }
  89
  90 /* FIXME: who wants to use this? */
  91 int
  92 cio_get_options (struct subchannel *sch)
  93 {
  94        int flags;
  95
  96        flags = 0;
  97        if (sch->options.suspend)
  98                 flags |= DOIO_ALLOW_SUSPEND;
  99        if (sch->options.prefetch)
 100                 flags |= DOIO_DENY_PREFETCH;
 101        if (sch->options.inter)
 102                 flags |= DOIO_SUPPRESS_INTER;
 103        return flags;
 104 }
 105
 106 /*
 107  * Use tpi to get a pending interrupt, call the interrupt handler and
 108  * return a pointer to the subchannel structure.
 109  */
 110 static int
 111 cio_tpi(void)
 112 {
 113         struct tpi_info *tpi_info;
 114         struct subchannel *sch;
 115         struct irb *irb;
 116
 117         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 118         if (tpi (NULL) != 1)
 119                 return 0;
 120         irb = (struct irb *) __LC_IRB;
 121         /* Store interrupt response block to lowcore. */
 122         if (tsch (tpi_info->schid, irb) != 0)
 123                 /* Not status pending or not operational. */
 124                 return 1;
 125         sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 126         if (!sch)
 127                 return 1;
 128         local_bh_disable();
 129         irq_enter ();
 130         spin_lock(sch->lock);
 131         memcpy (&sch->schib.scsw, &irb->scsw, sizeof (struct scsw));
 132         if (sch->driver && sch->driver->irq)
 133                 sch->driver->irq(sch);
 134         spin_unlock(sch->lock);
 135         irq_exit ();
 136         _local_bh_enable();
 137         return 1;
 138 }
 139
 140 static int
 141 cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
 142 {
 143         char dbf_text[15];
 144
 145         if (lpm != 0)
 146                 sch->lpm &= ~lpm;
 147         else
 148                 sch->lpm = 0;
 149
 150         stsch (sch->schid, &sch->schib);
 151
 152         CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
 153                       "subchannel 0.%x.%04x!\n", sch->schid.ssid,
 154                       sch->schid.sch_no);
 155         sprintf(dbf_text, "no%s", sch->dev.bus_id);
 156         CIO_TRACE_EVENT(0, dbf_text);
 157         CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
 158
 159         return (sch->lpm ? -EACCES : -ENODEV);
 160 }
 161
 162 int
 163 cio_start_key (struct subchannel *sch,  /* subchannel structure */
 164                struct ccw1 * cpa,       /* logical channel prog addr */
 165                __u8 lpm,                /* logical path mask */
 166                __u8 key)                /* storage key */
 167 {
 168         char dbf_txt[15];
 169         int ccode;
 170         struct orb *orb;
 171
 172         CIO_TRACE_EVENT(4, "stIO");
 173         CIO_TRACE_EVENT(4, sch->dev.bus_id);
 174
 175         orb = &to_io_private(sch)->orb;
 176         /* sch is always under 2G. */
 177         orb->intparm = (u32)(addr_t)sch;
 178         orb->fmt = 1;
 179
 180         orb->pfch = sch->options.prefetch == 0;
 181         orb->spnd = sch->options.suspend;
 182         orb->ssic = sch->options.suspend && sch->options.inter;
 183         orb->lpm = (lpm != 0) ? lpm : sch->lpm;
 184 #ifdef CONFIG_64BIT
 185         /*
 186          * for 64 bit we always support 64 bit IDAWs with 4k page size only
 187          */
 188         orb->c64 = 1;
 189         orb->i2k = 0;
 190 #endif
 191         orb->key = key >> 4;
 192         /* issue "Start Subchannel" */
 193         orb->cpa = (__u32) __pa(cpa);
 194         ccode = ssch(sch->schid, orb);
 195
 196         /* process condition code */
 197         sprintf(dbf_txt, "ccode:%d", ccode);
 198         CIO_TRACE_EVENT(4, dbf_txt);
 199
 200         switch (ccode) {
 201         case 0:
 202                 /*
 203                  * initialize device status information
 204                  */
 205                 sch->schib.scsw.actl |= SCSW_ACTL_START_PEND;
 206                 return 0;
 207         case 1:         /* status pending */
 208         case 2:         /* busy */
 209                 return -EBUSY;
 210         default:                /* device/path not operational */
 211                 return cio_start_handle_notoper(sch, lpm);
 212         }
 213 }
 214
 215 int
 216 cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
 217 {
 218         return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
 219 }
 220
 221 /*
 222  * resume suspended I/O operation
 223  */
 224 int
 225 cio_resume (struct subchannel *sch)
 226 {
 227         char dbf_txt[15];
 228         int ccode;
 229
 230         CIO_TRACE_EVENT (4, "resIO");
 231         CIO_TRACE_EVENT (4, sch->dev.bus_id);
 232
 233         ccode = rsch (sch->schid);
 234
 235         sprintf (dbf_txt, "ccode:%d", ccode);
 236         CIO_TRACE_EVENT (4, dbf_txt);
 237
 238         switch (ccode) {
 239         case 0:
 240                 sch->schib.scsw.actl |= SCSW_ACTL_RESUME_PEND;
 241                 return 0;
 242         case 1:
 243                 return -EBUSY;
 244         case 2:
 245                 return -EINVAL;
 246         default:
 247                 /*
 248                  * useless to wait for request completion
 249                  *  as device is no longer operational !
 250                  */
 251                 return -ENODEV;
 252         }
 253 }
 254
 255 /*
 256  * halt I/O operation
 257  */
 258 int
 259 cio_halt(struct subchannel *sch)
 260 {
 261         char dbf_txt[15];
 262         int ccode;
 263
 264         if (!sch)
 265                 return -ENODEV;
 266
 267         CIO_TRACE_EVENT (2, "haltIO");
 268         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 269
 270         /*
 271          * Issue "Halt subchannel" and process condition code
 272          */
 273         ccode = hsch (sch->schid);
 274
 275         sprintf (dbf_txt, "ccode:%d", ccode);
 276         CIO_TRACE_EVENT (2, dbf_txt);
 277
 278         switch (ccode) {
 279         case 0:
 280                 sch->schib.scsw.actl |= SCSW_ACTL_HALT_PEND;
 281                 return 0;
 282         case 1:         /* status pending */
 283         case 2:         /* busy */
 284                 return -EBUSY;
 285         default:                /* device not operational */
 286                 return -ENODEV;
 287         }
 288 }
 289
 290 /*
 291  * Clear I/O operation
 292  */
 293 int
 294 cio_clear(struct subchannel *sch)
 295 {
 296         char dbf_txt[15];
 297         int ccode;
 298
 299         if (!sch)
 300                 return -ENODEV;
 301
 302         CIO_TRACE_EVENT (2, "clearIO");
 303         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 304
 305         /*
 306          * Issue "Clear subchannel" and process condition code
 307          */
 308         ccode = csch (sch->schid);
 309
 310         sprintf (dbf_txt, "ccode:%d", ccode);
 311         CIO_TRACE_EVENT (2, dbf_txt);
 312
 313         switch (ccode) {
 314         case 0:
 315                 sch->schib.scsw.actl |= SCSW_ACTL_CLEAR_PEND;
 316                 return 0;
 317         default:                /* device not operational */
 318                 return -ENODEV;
 319         }
 320 }
 321
 322 /*
 323  * Function: cio_cancel
 324  * Issues a "Cancel Subchannel" on the specified subchannel
 325  * Note: We don't need any fancy intparms and flags here
 326  *       since xsch is executed synchronously.
 327  * Only for common I/O internal use as for now.
 328  */
 329 int
 330 cio_cancel (struct subchannel *sch)
 331 {
 332         char dbf_txt[15];
 333         int ccode;
 334
 335         if (!sch)
 336                 return -ENODEV;
 337
 338         CIO_TRACE_EVENT (2, "cancelIO");
 339         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 340
 341         ccode = xsch (sch->schid);
 342
 343         sprintf (dbf_txt, "ccode:%d", ccode);
 344         CIO_TRACE_EVENT (2, dbf_txt);
 345
 346         switch (ccode) {
 347         case 0:         /* success */
 348                 /* Update information in scsw. */
 349                 stsch (sch->schid, &sch->schib);
 350                 return 0;
 351         case 1:         /* status pending */
 352                 return -EBUSY;
 353         case 2:         /* not applicable */
 354                 return -EINVAL;
 355         default:        /* not oper */
 356                 return -ENODEV;
 357         }
 358 }
 359
 360 /*
 361  * Function: cio_modify
 362  * Issues a "Modify Subchannel" on the specified subchannel
 363  */
 364 int
 365 cio_modify (struct subchannel *sch)
 366 {
 367         int ccode, retry, ret;
 368
 369         ret = 0;
 370         for (retry = 0; retry < 5; retry++) {
 371                 ccode = msch_err (sch->schid, &sch->schib);
 372                 if (ccode < 0)  /* -EIO if msch gets a program check. */
 373                         return ccode;
 374                 switch (ccode) {
 375                 case 0: /* successfull */
 376                         return 0;
 377                 case 1: /* status pending */
 378                         return -EBUSY;
 379                 case 2: /* busy */
 380                         udelay (100);   /* allow for recovery */
 381                         ret = -EBUSY;
 382                         break;
 383                 case 3: /* not operational */
 384                         return -ENODEV;
 385                 }
 386         }
 387         return ret;
 388 }
 389
 390 /*
 391  * Enable subchannel.
 392  */
 393 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 394 {
 395         char dbf_txt[15];
 396         int ccode;
 397         int retry;
 398         int ret;
 399
 400         CIO_TRACE_EVENT (2, "ensch");
 401         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 402
 403         if (sch_is_pseudo_sch(sch))
 404                 return -EINVAL;
 405         ccode = stsch (sch->schid, &sch->schib);
 406         if (ccode)
 407                 return -ENODEV;
 408
 409         for (retry = 5, ret = 0; retry > 0; retry--) {
 410                 sch->schib.pmcw.ena = 1;
 411                 sch->schib.pmcw.isc = sch->isc;
 412                 sch->schib.pmcw.intparm = intparm;
 413                 ret = cio_modify(sch);
 414                 if (ret == -ENODEV)
 415                         break;
 416                 if (ret == -EIO)
 417                         /*
 418                          * Got a program check in cio_modify. Try without
 419                          * the concurrent sense bit the next time.
 420                          */
 421                         sch->schib.pmcw.csense = 0;
 422                 if (ret == 0) {
 423                         stsch (sch->schid, &sch->schib);
 424                         if (sch->schib.pmcw.ena)
 425                                 break;
 426                 }
 427                 if (ret == -EBUSY) {
 428                         struct irb irb;
 429                         if (tsch(sch->schid, &irb) != 0)
 430                                 break;
 431                 }
 432         }
 433         sprintf (dbf_txt, "ret:%d", ret);
 434         CIO_TRACE_EVENT (2, dbf_txt);
 435         return ret;
 436 }
 437
 438 /*
 439  * Disable subchannel.
 440  */
 441 int
 442 cio_disable_subchannel (struct subchannel *sch)
 443 {
 444         char dbf_txt[15];
 445         int ccode;
 446         int retry;
 447         int ret;
 448
 449         CIO_TRACE_EVENT (2, "dissch");
 450         CIO_TRACE_EVENT (2, sch->dev.bus_id);
 451
 452         if (sch_is_pseudo_sch(sch))
 453                 return 0;
 454         ccode = stsch (sch->schid, &sch->schib);
 455         if (ccode == 3)         /* Not operational. */
 456                 return -ENODEV;
 457
 458         if (sch->schib.scsw.actl != 0)
 459                 /*
 460                  * the disable function must not be called while there are
 461                  *  requests pending for completion !
 462                  */
 463                 return -EBUSY;
 464
 465         for (retry = 5, ret = 0; retry > 0; retry--) {
 466                 sch->schib.pmcw.ena = 0;
 467                 ret = cio_modify(sch);
 468                 if (ret == -ENODEV)
 469                         break;
 470                 if (ret == -EBUSY)
 471                         /*
 472                          * The subchannel is busy or status pending.
 473                          * We'll disable when the next interrupt was delivered
 474                          * via the state machine.
 475                          */
 476                         break;
 477                 if (ret == 0) {
 478                         stsch (sch->schid, &sch->schib);
 479                         if (!sch->schib.pmcw.ena)
 480                                 break;
 481                 }
 482         }
 483         sprintf (dbf_txt, "ret:%d", ret);
 484         CIO_TRACE_EVENT (2, dbf_txt);
 485         return ret;
 486 }
 487
 488 int cio_create_sch_lock(struct subchannel *sch)
 489 {
 490         sch->lock = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
 491         if (!sch->lock)
 492                 return -ENOMEM;
 493         spin_lock_init(sch->lock);
 494         return 0;
 495 }
 496
 497 /*
 498  * cio_validate_subchannel()
 499  *
 500  * Find out subchannel type and initialize struct subchannel.
 501  * Return codes:
 502  *   SUBCHANNEL_TYPE_IO for a normal io subchannel
 503  *   SUBCHANNEL_TYPE_CHSC for a chsc subchannel
 504  *   SUBCHANNEL_TYPE_MESSAGE for a messaging subchannel
 505  *   SUBCHANNEL_TYPE_ADM for a adm(?) subchannel
 506  *   -ENXIO for non-defined subchannels
 507  *   -ENODEV for subchannels with invalid device number or blacklisted devices
 508  */
 509 int
 510 cio_validate_subchannel (struct subchannel *sch, struct subchannel_id schid)
 511 {
 512         char dbf_txt[15];
 513         int ccode;
 514         int err;
 515
 516         sprintf (dbf_txt, "valsch%x", schid.sch_no);
 517         CIO_TRACE_EVENT (4, dbf_txt);
 518
 519         /* Nuke all fields. */
 520         memset(sch, 0, sizeof(struct subchannel));
 521
 522         sch->schid = schid;
 523         if (cio_is_console(schid)) {
 524                 sch->lock = cio_get_console_lock();
 525         } else {
 526                 err = cio_create_sch_lock(sch);
 527                 if (err)
 528                         goto out;
 529         }
 530         mutex_init(&sch->reg_mutex);
 531         /* Set a name for the subchannel */
 532         snprintf (sch->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x", schid.ssid,
 533                   schid.sch_no);
 534
 535         /*
 536          * The first subchannel that is not-operational (ccode==3)
 537          *  indicates that there aren't any more devices available.
 538          * If stsch gets an exception, it means the current subchannel set
 539          *  is not valid.
 540          */
 541         ccode = stsch_err (schid, &sch->schib);
 542         if (ccode) {
 543                 err = (ccode == 3) ? -ENXIO : ccode;
 544                 goto out;
 545         }
 546         /* Copy subchannel type from path management control word. */
 547         sch->st = sch->schib.pmcw.st;
 548
 549         /*
 550          * ... just being curious we check for non I/O subchannels
 551          */
 552         if (sch->st != 0) {
 553                 CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports "
 554                               "non-I/O subchannel type %04X\n",
 555                               sch->schid.ssid, sch->schid.sch_no, sch->st);
 556                 /* We stop here for non-io subchannels. */
 557                 err = sch->st;
 558                 goto out;
 559         }
 560
 561         /* Initialization for io subchannels. */
 562         if (!css_sch_is_valid(&sch->schib)) {
 563                 err = -ENODEV;
 564                 goto out;
 565         }
 566
 567         /* Devno is valid. */
 568         if (is_blacklisted (sch->schid.ssid, sch->schib.pmcw.dev)) {
 569                 /*
 570                  * This device must not be known to Linux. So we simply
 571                  * say that there is no device and return ENODEV.
 572                  */
 573                 CIO_MSG_EVENT(6, "Blacklisted device detected "
 574                               "at devno %04X, subchannel set %x\n",
 575                               sch->schib.pmcw.dev, sch->schid.ssid);
 576                 err = -ENODEV;
 577                 goto out;
 578         }
 579         if (cio_is_console(sch->schid))
 580                 sch->opm = 0xff;
 581         else
 582                 sch->opm = chp_get_sch_opm(sch);
 583         sch->lpm = sch->schib.pmcw.pam & sch->opm;
 584         sch->isc = 3;
 585
 586         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X "
 587                       "- PIM = %02X, PAM = %02X, POM = %02X\n",
 588                       sch->schib.pmcw.dev, sch->schid.ssid,
 589                       sch->schid.sch_no, sch->schib.pmcw.pim,
 590                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
 591
 592         /*
 593          * We now have to initially ...
 594          *  ... enable "concurrent sense"
 595          *  ... enable "multipath mode" if more than one
 596          *        CHPID is available. This is done regardless
 597          *        whether multiple paths are available for us.
 598          */
 599         sch->schib.pmcw.csense = 1;     /* concurrent sense */
 600         sch->schib.pmcw.ena = 0;
 601         if ((sch->lpm & (sch->lpm - 1)) != 0)
 602                 sch->schib.pmcw.mp = 1; /* multipath mode */
 603         /* clean up possible residual cmf stuff */
 604         sch->schib.pmcw.mme = 0;
 605         sch->schib.pmcw.mbfc = 0;
 606         sch->schib.pmcw.mbi = 0;
 607         sch->schib.mba = 0;
 608         return 0;
 609 out:
 610         if (!cio_is_console(schid))
 611                 kfree(sch->lock);
 612         sch->lock = NULL;
 613         return err;
 614 }
 615
 616 /*
 617  * do_IRQ() handles all normal I/O device IRQ's (the special
 618  *          SMP cross-CPU interrupts have their own specific
 619  *          handlers).
 620  *
 621  */
 622 void
 623 do_IRQ (struct pt_regs *regs)
 624 {
 625         struct tpi_info *tpi_info;
 626         struct subchannel *sch;
 627         struct irb *irb;
 628         struct pt_regs *old_regs;
 629
 630         old_regs = set_irq_regs(regs);
 631         irq_enter();
 632         s390_idle_check();
 633         if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
 634                 /* Serve timer interrupts first. */
 635                 clock_comparator_work();
 636         /*
 637          * Get interrupt information from lowcore
 638          */
 639         tpi_info = (struct tpi_info *) __LC_SUBCHANNEL_ID;
 640         irb = (struct irb *) __LC_IRB;
 641         do {
 642                 kstat_cpu(smp_processor_id()).irqs[IO_INTERRUPT]++;
 643                 /*
 644                  * Non I/O-subchannel thin interrupts are processed differently
 645                  */
 646                 if (tpi_info->adapter_IO == 1 &&
 647                     tpi_info->int_type == IO_INTERRUPT_TYPE) {
 648                         do_adapter_IO();
 649                         continue;
 650                 }
 651                 sch = (struct subchannel *)(unsigned long)tpi_info->intparm;
 652                 if (!sch) {
 653                         /* Clear pending interrupt condition. */
 654                         tsch(tpi_info->schid, irb);
 655                         continue;
 656                 }
 657                 spin_lock(sch->lock);
 658                 /* Store interrupt response block to lowcore. */
 659                 if (tsch(tpi_info->schid, irb) == 0) {
 660                         /* Keep subchannel information word up to date. */
 661                         memcpy (&sch->schib.scsw, &irb->scsw,
 662                                 sizeof (irb->scsw));
 663                         /* Call interrupt handler if there is one. */
 664                         if (sch->driver && sch->driver->irq)
 665                                 sch->driver->irq(sch);
 666                 }
 667                 spin_unlock(sch->lock);
 668                 /*
 669                  * Are more interrupts pending?
 670                  * If so, the tpi instruction will update the lowcore
 671                  * to hold the info for the next interrupt.
 672                  * We don't do this for VM because a tpi drops the cpu
 673                  * out of the sie which costs more cycles than it saves.
 674                  */
 675         } while (!MACHINE_IS_VM && tpi (NULL) != 0);
 676         irq_exit();
 677         set_irq_regs(old_regs);
 678 }
 679
 680 #ifdef CONFIG_CCW_CONSOLE
 681 static struct subchannel console_subchannel;
 682 static struct io_subchannel_private console_priv;
 683 static int console_subchannel_in_use;
 684
 685 void *cio_get_console_priv(void)
 686 {
 687         return &console_priv;
 688 }
 689
 690 /*
 691  * busy wait for the next interrupt on the console
 692  */
 693 void wait_cons_dev(void)
 694         __releases(console_subchannel.lock)
 695         __acquires(console_subchannel.lock)
 696 {
 697         unsigned long cr6      __attribute__ ((aligned (8)));
 698         unsigned long save_cr6 __attribute__ ((aligned (8)));
 699
 700         /*
 701          * before entering the spinlock we may already have
 702          * processed the interrupt on a different CPU...
 703          */
 704         if (!console_subchannel_in_use)
 705                 return;
 706
 707         /* disable all but isc 7 (console device) */
 708         __ctl_store (save_cr6, 6, 6);
 709         cr6 = 0x01000000;
 710         __ctl_load (cr6, 6, 6);
 711
 712         do {
 713                 spin_unlock(console_subchannel.lock);
 714                 if (!cio_tpi())
 715                         cpu_relax();
 716                 spin_lock(console_subchannel.lock);
 717         } while (console_subchannel.schib.scsw.actl != 0);
 718         /*
 719          * restore previous isc value
 720          */
 721         __ctl_load (save_cr6, 6, 6);
 722 }
 723
 724 static int
 725 cio_test_for_console(struct subchannel_id schid, void *data)
 726 {
 727         if (stsch_err(schid, &console_subchannel.schib) != 0)
 728                 return -ENXIO;
 729         if ((console_subchannel.schib.pmcw.st == SUBCHANNEL_TYPE_IO) &&
 730             console_subchannel.schib.pmcw.dnv &&
 731             (console_subchannel.schib.pmcw.dev == console_devno)) {
 732                 console_irq = schid.sch_no;
 733                 return 1; /* found */
 734         }
 735         return 0;
 736 }
 737
 738
 739 static int
 740 cio_get_console_sch_no(void)
 741 {
 742         struct subchannel_id schid;
 743
 744         init_subchannel_id(&schid);
 745         if (console_irq != -1) {
 746                 /* VM provided us with the irq number of the console. */
 747                 schid.sch_no = console_irq;
 748                 if (stsch(schid, &console_subchannel.schib) != 0 ||
 749                     (console_subchannel.schib.pmcw.st != SUBCHANNEL_TYPE_IO) ||
 750                     !console_subchannel.schib.pmcw.dnv)
 751                         return -1;
 752                 console_devno = console_subchannel.schib.pmcw.dev;
 753         } else if (console_devno != -1) {
 754                 /* At least the console device number is known. */
 755                 for_each_subchannel(cio_test_for_console, NULL);
 756                 if (console_irq == -1)
 757                         return -1;
 758         } else {
 759                 /* unlike in 2.4, we cannot autoprobe here, since
 760                  * the channel subsystem is not fully initialized.
 761                  * With some luck, the HWC console can take over */
 762                 printk(KERN_WARNING "cio: No ccw console found!\n");
 763                 return -1;
 764         }
 765         return console_irq;
 766 }
 767
 768 struct subchannel *
 769 cio_probe_console(void)
 770 {
 771         int sch_no, ret;
 772         struct subchannel_id schid;
 773
 774         if (xchg(&console_subchannel_in_use, 1) != 0)
 775                 return ERR_PTR(-EBUSY);
 776         sch_no = cio_get_console_sch_no();
 777         if (sch_no == -1) {
 778                 console_subchannel_in_use = 0;
 779                 return ERR_PTR(-ENODEV);
 780         }
 781         memset(&console_subchannel, 0, sizeof(struct subchannel));
 782         init_subchannel_id(&schid);
 783         schid.sch_no = sch_no;
 784         ret = cio_validate_subchannel(&console_subchannel, schid);
 785         if (ret) {
 786                 console_subchannel_in_use = 0;
 787                 return ERR_PTR(-ENODEV);
 788         }
 789
 790         /*
 791          * enable console I/O-interrupt subclass 7
 792          */
 793         ctl_set_bit(6, 24);
 794         console_subchannel.isc = 7;
 795         console_subchannel.schib.pmcw.isc = 7;
 796         console_subchannel.schib.pmcw.intparm =
 797                 (u32)(addr_t)&console_subchannel;
 798         ret = cio_modify(&console_subchannel);
 799         if (ret) {
 800                 console_subchannel_in_use = 0;
 801                 return ERR_PTR(ret);
 802         }
 803         return &console_subchannel;
 804 }
 805
 806 void
 807 cio_release_console(void)
 808 {
 809         console_subchannel.schib.pmcw.intparm = 0;
 810         cio_modify(&console_subchannel);
 811         ctl_clear_bit(6, 24);
 812         console_subchannel_in_use = 0;
 813 }
 814
 815 /* Bah... hack to catch console special sausages. */
 816 int
 817 cio_is_console(struct subchannel_id schid)
 818 {
 819         if (!console_subchannel_in_use)
 820                 return 0;
 821         return schid_equal(&schid, &console_subchannel.schid);
 822 }
 823
 824 struct subchannel *
 825 cio_get_console_subchannel(void)
 826 {
 827         if (!console_subchannel_in_use)
 828                 return NULL;
 829         return &console_subchannel;
 830 }
 831
 832 #endif
 833 static int
 834 __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
 835 {
 836         int retry, cc;
 837
 838         cc = 0;
 839         for (retry=0;retry<3;retry++) {
 840                 schib->pmcw.ena = 0;
 841                 cc = msch(schid, schib);
 842                 if (cc)
 843                         return (cc==3?-ENODEV:-EBUSY);
 844                 stsch(schid, schib);
 845                 if (!schib->pmcw.ena)
 846                         return 0;
 847         }
 848         return -EBUSY; /* uhm... */
 849 }
 850
 851 /* we can't use the normal udelay here, since it enables external interrupts */
 852
 853 static void udelay_reset(unsigned long usecs)
 854 {
 855         uint64_t start_cc, end_cc;
 856
 857         asm volatile ("STCK %0" : "=m" (start_cc));
 858         do {
 859                 cpu_relax();
 860                 asm volatile ("STCK %0" : "=m" (end_cc));
 861         } while (((end_cc - start_cc)/4096) < usecs);
 862 }
 863
 864 static int
 865 __clear_subchannel_easy(struct subchannel_id schid)
 866 {
 867         int retry;
 868
 869         if (csch(schid))
 870                 return -ENODEV;
 871         for (retry=0;retry<20;retry++) {
 872                 struct tpi_info ti;
 873
 874                 if (tpi(&ti)) {
 875                         tsch(ti.schid, (struct irb *)__LC_IRB);
 876                         if (schid_equal(&ti.schid, &schid))
 877                                 return 0;
 878                 }
 879                 udelay_reset(100);
 880         }
 881         return -EBUSY;
 882 }
 883
 884 static int pgm_check_occured;
 885
 886 static void cio_reset_pgm_check_handler(void)
 887 {
 888         pgm_check_occured = 1;
 889 }
 890
 891 static int stsch_reset(struct subchannel_id schid, volatile struct schib *addr)
 892 {
 893         int rc;
 894
 895         pgm_check_occured = 0;
 896         s390_base_pgm_handler_fn = cio_reset_pgm_check_handler;
 897         rc = stsch(schid, addr);
 898         s390_base_pgm_handler_fn = NULL;
 899
 900         /* The program check handler could have changed pgm_check_occured. */
 901         barrier();
 902
 903         if (pgm_check_occured)
 904                 return -EIO;
 905         else
 906                 return rc;
 907 }
 908
 909 static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 910 {
 911         struct schib schib;
 912
 913         if (stsch_reset(schid, &schib))
 914                 return -ENXIO;
 915         if (!schib.pmcw.ena)
 916                 return 0;
 917         switch(__disable_subchannel_easy(schid, &schib)) {
 918         case 0:
 919         case -ENODEV:
 920                 break;
 921         default: /* -EBUSY */
 922                 if (__clear_subchannel_easy(schid))
 923                         break; /* give up... */
 924                 stsch(schid, &schib);
 925                 __disable_subchannel_easy(schid, &schib);
 926         }
 927         return 0;
 928 }
 929
 930 static atomic_t chpid_reset_count;
 931
 932 static void s390_reset_chpids_mcck_handler(void)
 933 {
 934         struct crw crw;
 935         struct mci *mci;
 936
 937         /* Check for pending channel report word. */
 938         mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
 939         if (!mci->cp)
 940                 return;
 941         /* Process channel report words. */
 942         while (stcrw(&crw) == 0) {
 943                 /* Check for responses to RCHP. */
 944                 if (crw.slct && crw.rsc == CRW_RSC_CPATH)
 945                         atomic_dec(&chpid_reset_count);
 946         }
 947 }
 948
 949 #define RCHP_TIMEOUT (30 * USEC_PER_SEC)
 950 static void css_reset(void)
 951 {
 952         int i, ret;
 953         unsigned long long timeout;
 954         struct chp_id chpid;
 955
 956         /* Reset subchannels. */
 957         for_each_subchannel(__shutdown_subchannel_easy,  NULL);
 958         /* Reset channel paths. */
 959         s390_base_mcck_handler_fn = s390_reset_chpids_mcck_handler;
 960         /* Enable channel report machine checks. */
 961         __ctl_set_bit(14, 28);
 962         /* Temporarily reenable machine checks. */
 963         local_mcck_enable();
 964         chp_id_init(&chpid);
 965         for (i = 0; i <= __MAX_CHPID; i++) {
 966                 chpid.id = i;
 967                 ret = rchp(chpid);
 968                 if ((ret == 0) || (ret == 2))
 969                         /*
 970                          * rchp either succeeded, or another rchp is already
 971                          * in progress. In either case, we'll get a crw.
 972                          */
 973                         atomic_inc(&chpid_reset_count);
 974         }
 975         /* Wait for machine check for all channel paths. */
 976         timeout = get_clock() + (RCHP_TIMEOUT << 12);
 977         while (atomic_read(&chpid_reset_count) != 0) {
 978                 if (get_clock() > timeout)
 979                         break;
 980                 cpu_relax();
 981         }
 982         /* Disable machine checks again. */
 983         local_mcck_disable();
 984         /* Disable channel report machine checks. */
 985         __ctl_clear_bit(14, 28);
 986         s390_base_mcck_handler_fn = NULL;
 987 }
 988
 989 static struct reset_call css_reset_call = {
 990         .fn = css_reset,
 991 };
 992
 993 static int __init init_css_reset_call(void)
 994 {
 995         atomic_set(&chpid_reset_count, 0);
 996         register_reset_call(&css_reset_call);
 997         return 0;
 998 }
 999
1000 arch_initcall(init_css_reset_call);
1001
1002 struct sch_match_id {
1003         struct subchannel_id schid;
1004         struct ccw_dev_id devid;
1005         int rc;
1006 };
1007
1008 static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
1009 {
1010         struct schib schib;
1011         struct sch_match_id *match_id = data;
1012
1013         if (stsch_reset(schid, &schib))
1014                 return -ENXIO;
1015         if ((schib.pmcw.st == SUBCHANNEL_TYPE_IO) && schib.pmcw.dnv &&
1016             (schib.pmcw.dev == match_id->devid.devno) &&
1017             (schid.ssid == match_id->devid.ssid)) {
1018                 match_id->schid = schid;
1019                 match_id->rc = 0;
1020                 return 1;
1021         }
1022         return 0;
1023 }
1024
1025 static int reipl_find_schid(struct ccw_dev_id *devid,
1026                             struct subchannel_id *schid)
1027 {
1028         struct sch_match_id match_id;
1029
1030         match_id.devid = *devid;
1031         match_id.rc = -ENODEV;
1032         for_each_subchannel(__reipl_subchannel_match, &match_id);
1033         if (match_id.rc == 0)
1034                 *schid = match_id.schid;
1035         return match_id.rc;
1036 }
1037
1038 extern void do_reipl_asm(__u32 schid);
1039
1040 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
1041 void reipl_ccw_dev(struct ccw_dev_id *devid)
1042 {
1043         struct subchannel_id schid;
1044
1045         s390_reset_system();
1046         if (reipl_find_schid(devid, &schid) != 0)
1047                 panic("IPL Device not found\n");
1048         do_reipl_asm(*((__u32*)&schid));
1049 }
1050
1051 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
1052 {
1053         struct subchannel_id schid;
1054         struct schib schib;
1055
1056         schid = *(struct subchannel_id *)__LC_SUBCHANNEL_ID;
1057         if (!schid.one)
1058                 return -ENODEV;
1059         if (stsch(schid, &schib))
1060                 return -ENODEV;
1061         if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
1062                 return -ENODEV;
1063         if (!schib.pmcw.dnv)
1064                 return -ENODEV;
1065         iplinfo->devno = schib.pmcw.dev;
1066         iplinfo->is_qdio = schib.pmcw.qf;
1067         return 0;
1068 }